Electrosurgical units used for cautery, fulguration and electrocoagulation utilize ground electrodes in engagement with the patient to ground the patient. An example of a ground plate electrode is disclosed by Bolduc in U.S. Pat. No. 3,543,760. Electrosurgical units utilize a high frequency current in a localized area to effect cutting and coagulation action. These high frequency signals establish interference noise signals which inhibit the monitoring of ECG signals during the electrosurgical operation. The conventional ECG recording equipment is not compatible with the electrosurgical machines. The ECG monitoring units use separate electrodes attached to the patient's extremities, as shown, for example, in U.S. Pat. No. 3,029,820.